The invention relates to a method for optimizing the use of network resources for transmission of data frames, e.g. voice frames between network units in an IP-packet supporting network. The data frames being obtained from data samples that are formatted and to which a data frame header is added. Each codec having a different mouth-to-ear transmission delay budgets for the data frame derived from it.
Transmission of packetized data signals in an IP-supporting network may require a significant part of network resources. This is particularly true when the data signals are voice signals and when a large number of user streams arriving together needs to be transmitted between network routers and for instance between two multimedia gateways [MGW] of an Universal Mobile Telecommunication System [UMTS] network. As known, all the user voice streams collected at the level of an ingress router do not necessarily come from the same type of codec and some codecs have longer tolerable mouth-to-ear transmission delays than others for obtaining good quality communication, defined as “delay budgets”. Particularly, use of adaptative multi-rate [AMR] and of adaptative multi-rate wideband [AMR-WB] codecs for voice coding is opted by the UMTS standardization organization 3GPP, and accordingly, codecs producing a discrete number of different codec rates are authorized. Dynamical changes of codec rates during calls are foreseen taking for instance into account changes of the quality of transmission for the voice over the air link and optimization arguments for bandwidth usage. As known adequate sharing of the available bandwidth on a link is very important.
A known approach to reduce bandwidth needed for transmission implies the multiplexing of several data frames in a same packet or cell for an Internet protocol IP based transport of data frames, this being advocated in the UMTS terrestrial radio access network UTRAN standardization process promoted by 3GPP. A multiplexing protocol over IP, such as composite Internet protocol is proposed for this purpose, it is also applicable to other telecommunication networks where multiplexing of payloads is possible.
If the data frames to be multiplexed in a same IP cell are voice frames involving different delay requirements, the delay for this IP cell needs to be the lowest of the individual delay bounds. Stricter delay bounds mean higher resource reservations in the IP network and consequently a less efficient use of the network resources and a higher cost for the end-user.